/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.mock.web.test;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;

import java.util.*;

/**
 * Internal helper class that serves as value holder for request headers.
 *
 * @author Juergen Hoeller
 * @author Rick Evans
 * @since 2.0.1
 */
class HeaderValueHolder {

    private final List<Object> values = new LinkedList<>();

    /**
     * Find a HeaderValueHolder by name, ignoring casing.
     *
     * @param headers the Map of header names to HeaderValueHolders
     * @param name    the name of the desired header
     * @return the corresponding HeaderValueHolder, or {@code null} if none found
     */
    @Nullable
    public static HeaderValueHolder getByName(Map<String, HeaderValueHolder> headers, String name) {
        Assert.notNull(name, "Header name must not be null");
        for (String headerName : headers.keySet()) {
            if (headerName.equalsIgnoreCase(name)) {
                return headers.get(headerName);
            }
        }
        return null;
    }

    public void addValue(Object value) {
        this.values.add(value);
    }

    public void addValues(Collection<?> values) {
        this.values.addAll(values);
    }

    public void addValueArray(Object values) {
        CollectionUtils.mergeArrayIntoCollection(values, this.values);
    }

    public List<Object> getValues() {
        return Collections.unmodifiableList(this.values);
    }

    public List<String> getStringValues() {
        List<String> stringList = new ArrayList<>(this.values.size());
        for (Object value : this.values) {
            stringList.add(value.toString());
        }
        return Collections.unmodifiableList(stringList);
    }

    @Nullable
    public Object getValue() {
        return (!this.values.isEmpty() ? this.values.get(0) : null);
    }

    public void setValue(@Nullable Object value) {
        this.values.clear();
        if (value != null) {
            this.values.add(value);
        }
    }

    @Nullable
    public String getStringValue() {
        return (!this.values.isEmpty() ? String.valueOf(this.values.get(0)) : null);
    }

    @Override
    public String toString() {
        return this.values.toString();
    }

}
